[数据结构]顺序单链表插入

一，单链表插入操作

typedef struct NODE {
    struct NODE *link;
    int value;
}Node;

#include <stdlib.h>
#include <stdio.h>

#define FALSE 0
#define TRUE 1

int s_insert(Node **rootp,int new_value)  //root是一个指向Node的指针，所以指针root的指针类型是Node**
{
    Node *current;
    Node *new;
    Node *previous;

    current = *rootp;
    previous = NULL;

    while(current != NULL && current->value < new_value)
    {
        previous = current;
        current = current->link;
    }

    new = (Node*)malloc(sizeof(Node));
    if(new == NULL)
    {
        return FALSE;
    }
    new->value = new_value;

    new->link = current;
    if(previous == NULL)
    {
        *rootp = new;
    }
    else
    {
        previous->link = new;
    }
    return TRUE;
}